1. Field of the Invention
The present invention relates to an IC card connector device provided with equipment which is used by inserting and withdrawing an IC card thereinto and therefrom, and more specifically, to an eject mechanism for discharging a loaded IC card.
2. Description of the Related Art
Usually, IC card connector devices are schematically arranged such that they include a pin header unit in which a multiplicity of pin contacts to be connected to socket contacts in an IC card are disposed in a housing, frames for guiding the IC card when it is inserted or withdrawn, an eject mechanism for releasing the loaded IC card from the pin contacts, and the like. There are also known IC card connector devices which include a pin housing formed integrally with frames.
Conventionally, widely employed eject mechanisms are composed of a push rod held on the outside surface of a frame so as to reciprocate in the insertion/withdrawal direction of an IC card and an eject lever turnably supported by the frame or a pin housing with an end of the eject lever engaged with the push rod. When the push rod is pushed in an IC card connector device provided with this type of the eject mechanism in the state that the IC card is loaded, since the claw portion of the eject lever which turns in association with the push rod presses the IC card toward the operator's side, the operator can simply draw out the IC card with his/her fingers. However, this arrangement has such a drawback that since the push rod projects toward the operator's side in the state that the IC card is loaded, the IC card is discharged against the operator's intention by the erroneous operation of the projecting push rod.
Whereas, the IC card connector device disclosed in Japanese Unexamined Utility Model Publication No. 6-13072 comprises first and second transmission levers which couple a push rod with a slide plate through a link, a third transmission lever which is turnably supported by the first transmission lever and engaged with and disengaged from the second transmission lever and a heart-shaped cam mechanism which can hold the push rod at a push position and a first projecting position so that the push force of the push rod can be selectively transmitted to the slide plate in accordance with a projecting amount of the push rod. That is, when an IC card is loaded, the push rod is held at the push position and the third transmission lever is not engaged with the second transmission lever. However, when the push rod is projected up to the first projecting position by the heart-shaped cam mechanism and thereafter it is further pulled to a second projecting position on the operator's side, the third transmission lever is engaged with the second transmission lever at the second projecting position. Thus, when the push rod is pressed in the direction of the push position in this state, the press force is transmitted to the slide plate through the respective transmission levers so that the slide plate presses the IC card to the operator's side. Therefore, the IC card can be prevented from being discharged against the operator's intention in such a manner that the push rod is held at the push position while the IC card is connected and projected up to the push position only when the IC card is discharged.
As described above, according to the IC card connector device disclosed in the above publication, since the push rod is held at the push position while the IC card is connected and projected only when the IC card is discharged, the IC card can be prevented from being discharged against the operator's intention. Further, when the push rod is erroneously projected regardless of that the operator does not desire to discharge the IC card, the push rod can be held at the push position again without discharging the IC card by pushing the push rod from the first projecting position without pulling out it up to the second projecting position, whereby the operability of eject operation can be improved.
However, there is a problem that since the three transmission levers coupled with each other through the link are interposed between the push rod and the slide plate and the press force of the push rod is transmitted to or shut off from the slide plate in accordance with the attitude of the respective transmission levers, a large space is necessary to turn the respective transmission levers and the miniaturization of the IC card connector device is prevented by it. Since the respective transmission levers must be inevitably disposed to the top surface or bottom surface of an IC card insertion port because of the above reasons, and in particular, since a plurality of sets of the respective transmission levers must be disposed in a vertically piled state by securing a sufficient space in an IC card connector device which permits at least two IC cards to be inserted thereinto and withdrawn therefrom, there is caused a problem that the size of the IC card connector device is increased in a height direction. Further, the IC card connector device has a problem that eject operation is troublesome because it requires to perform operation three times in ordinary eject operation, that is, operation for projecting the push rod held at the push position up to the first projecting position, operation for pulling out the push rod located at the first projecting position up to the second projecting position and operation for pushing the push rod projected to the second projecting position to the push position. Further, there still remains a problem that when the push rod is erroneously projected up to the second projecting position, the IC card is discharged against the operator's intention.